Adjustable gastric banding systems provide an effective and substantially less invasive alternative to gastric bypass surgery and other conventional surgical weight loss procedures. Despite the sustained weight loss of invasive weight loss procedures, such as gastric bypass surgery, it has been recognized that sustained weight loss can also be achieved through a laparoscopically-placed gastric band, for example, the LAP-BAND® (Allergan, Inc., Irvine, Calif.) gastric band or the LAP-BAND AP® (Allergan, Inc., Irvine, Calif.) gastric band. Generally, gastric bands are placed about the cardia, or upper portion, of a patient's stomach forming a stoma that restricts food's passage into a lower portion of the stomach. When the stoma is of an appropriate size to be partially restricted by a gastric band, the tension on the upper portion of the stomach at rest and during food passage provides a feeling of satiety or fullness, thereby facilitating the reduction of the daily caloric intake. Unlike gastric bypass procedures, the gastric band apparatus are reversible and require no permanent modification to the gastrointestinal tract.
Over time, a stoma created by the gastric band may need an adjustment in order to maintain an appropriate size, which is neither too restrictive nor too passive. Accordingly, conventional gastric band systems provide a subcutaneous fluid access port connected to an expandable or inflatable portion of the gastric band. By adding fluid to or removing fluid from the inflatable portion by means of a hypodermic needle inserted into the access port, the effective size of the gastric band can be adjusted to provide a tighter or looser constriction.
It would be desirable to allow for non-invasive adjustment of gastric band constriction, for example, without use of the hypodermic needle. Thus, remotely adjustable gastric banding systems have been capable of non-invasive adjustment are described herein.